-- @owner: @li-xin12345
-- @date: 2023/8/3
-- @testpoint: 范围分区表，非压缩表改为压缩表
-- @history: Modified by li-xin12345 2025.3.24：研发代码变更，压缩率变化

--step1:建范围分区表并插入数据;expect:成功
drop table if exists t_alter_rowcompress_0018 cascade;
create table t_alter_rowcompress_0018(
  c1 integer,
  c2 char(50),
  c3 varchar(50),
  c4 integer
) partition by range(c1)(
  partition t_alter_rowcompress_0018_01
  values
    less than(1000),
    partition t_alter_rowcompress_0018_02
  values
    less than(2000),
    partition t_alter_rowcompress_0018_03
  values
    less than(3000),
    partition t_alter_rowcompress_0018_04
  values
    less than(maxvalue)
);
insert into t_alter_rowcompress_0018 values(generate_series(0, 2000),'test1','TEST2', 12365);

--step2:查看表文件占用磁盘大小，数据校验;expect:成功
select pg_size_pretty(pg_total_relation_size('t_alter_rowcompress_0018')) as table_size;
select checksum(t_alter_rowcompress_0018::text) from t_alter_rowcompress_0018;

--step3:修改表为压缩表，checkpoint;expect:成功
alter table t_alter_rowcompress_0018 set (compresstype = 1);
checkpoint;

--step4:再次查看表文件占用磁盘大小、数据校验;expect:表文件磁盘占用小于非压缩表，数据一致
select pg_size_pretty(pg_total_relation_size('t_alter_rowcompress_0018')) as table_size;
select checksum(t_alter_rowcompress_0018::text) from t_alter_rowcompress_0018;

--step5:查看压缩率;expect:成功
drop function if exists compress_func_findpath(character varying);
create or replace function compress_func_findpath(character varying)
returns character varying
language plpgsql
as
$body$
declare
relpath character varying;
begin
relpath = (select pg_relation_filepath(relname::regclass) from pg_class where relname = $1);
return relpath;
end;
$body$;
/

select is_compress, file_count, logic_size, physic_size, compress_ratio from pg_catalog.compress_ratio_info(compress_func_findpath('t_alter_rowcompress_0018'));

--step6:查看分区表信息;expect:成功
select relname, reloptions from pg_partition where relname like '%rowcompress_0018%' order by relname;

--step7:清理环境;expect:成功
drop table if exists t_alter_rowcompress_0018;
drop function if exists compress_func_findpath(character varying);